1. Technical Field
The present invention relates to an optical semiconductor lighting apparatus.
2. Description of the Related Art
Optical semiconductor devices such as light emitting diodes (LEDs) have is attracted increasing attention due to excellent advantages such as low power consumption, long lifespan, high durability, and excellent brightness, as compared with incandescent lamps or fluorescent lamps.
In particular, an optical semiconductor device is free from toxic or environmentally unfriendly substances such as mercury injected into a glass tube together with argon gas in manufacture of fluorescent lamps or mercury lamps, thereby providing environmentally friendly products.
In recent years, a lighting apparatus using an optical semiconductor device has been actively developed and studied in terms of light engines.
Particularly, as a lighting apparatus including an optical semiconductor device as a light source has been applied to outdoor lighting or security lighting, such a lighting apparatus needs to provide convenience in assembly and installation and to maintain waterproof performance even under outdoor conditions for a long period of time.
A conventional light emitting module needs to provide wide and uniform illumination using as few optical semiconductor devices as possible.
Accordingly, a conventional lighting apparatus employs lenses for spreading light emitted from the optical semiconductor devices.
In the conventional lighting apparatus, however, a relatively dark area can be generated between the lenses.
In addition, light emitted from the optical semiconductor device can be absorbed by protrusions on a heat sink before passing through an optical cover.
Meanwhile, it can be conceivable to provide a lighting apparatus in which at least one light emitting module including a heat sink is coupled to a housing.
In the light emitting module, the heat sink is provided at a rear side thereof with heat dissipation fins and at a front side thereof with a printed circuit board (PCB), on which optical semiconductor devices are mounted and respectively covered by lenses.
Here, the optical cover is assembled to the front side of the heat sink to cover the PCB, the optical semiconductor devices, and the lenses.
To fabricate such a conventional light emitting module, the lenses need to be placed corresponding to the optical semiconductor devices.
In addition, light emitted from the optical semiconductor devices passes through the optical cover after passing through the lenses, and is thus subjected to optical loss.
Further, moisture or other foreign matter is likely to enter the light emitting module through a gap between the optical cover and the heat sink.
Meanwhile, the lighting apparatus may include a plurality of light emitting modules as described above.
In this case, the lighting apparatus needs a complicated wire connection structure to supply power from a power source to the light emitting modules through a main power wire.
At this time, such a complicated wire connection structure increases manufacturing costs while reducing operation efficiency.
For the conventional lighting apparatus, since individual light emitting modules are connected to one another via the complicated wire connection structure, it is difficult to separate the individual light emitting modules from one another, thereby providing difficulty in replacement, repair and maintenance of the light emitting modules.
On the other hand, a conventional light engine is generally provided with a heat sink above a light emitting module, which includes an optical semiconductor device such as an LED, and thus has difficulty in natural convection cooling.
Currently, a light engine for outdoor products using optical semiconductor devices does not have such cooling performance.